1. Field of the Invention
This invention relates to a spring drive device with a coil spring as a drive source.
2. Background Art
A variety of spring drive source with coil springs as their drive sources have been proposed and put in practical use. Also, a variety of methods of increasing the torque of these drive sources have been proposed in the art.
In most of the spring drive devices which utilize coil springs as drive sources, one end of the spring is engaged with a stationary member such as a frame. Therefore, the spring drive devices suffer from the difficulty that it is rather difficult to assemble.